The probability of duodenal ulcer becoming cancerous is relatively small, which is closely related to the location and structure of duodenum. The earlier the treatment, the less likely it is to become cancerous. At present, the treatment of duodenal ulcer is very mature and standardized. More than 90% of duodenal ulcer patients are found to be infected with Helicobacter pylori, a bacterium that settles in the stomach but can cause duodenal ulcers through a series of complex mechanisms. Therefore, for patients with duodenal ulcers, whether active or scarred, H. pylori testing is mandatory and, if positive, standardized and relevant antimicrobial therapy is administered. If H. pylori is successfully eradicated, the ulcer can be cured and recurrence of the majority of ulcers is eliminated. Another reason for the development of duodenal ulcers is the use of aspirin and NSAIDs. Such patients need to stop taking them as much as other conditions allow and take drugs that inhibit gastric acid secretion, such as omeprazole-type drugs, which can basically heal in 4 to 8 weeks of treatment. However, such patients also need to be checked for H. pylori infection. Of course, there are other rare causes of duodenal ulcers, such as endocrine tumors, which are more specific. Targeted treatment is needed. Therefore, the probability of duodenal ulcer becoming cancerous is relatively small, and with timely and standardized treatment, it is possible to cure the ulcer and thus avoid its cancerous transformation.